1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
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  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
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 24 
 25 #ifndef SHARE_GC_G1_G1FULLGCPREPARETASK_HPP
 26 #define SHARE_GC_G1_G1FULLGCPREPARETASK_HPP
 27 
 28 #include "gc/g1/g1FullGCTask.hpp"
 29 #include "gc/g1/heapRegion.hpp"
 30 #include "memory/allocation.hpp"
 31 
 32 class G1CollectedHeap;
 33 class G1CMBitMap;
 34 class G1FullCollector;
 35 class G1FullGCCompactionPoint;
 36 class HeapRegion;
 37 
 38 // Determines the regions in the heap that should be part of the compaction and
 39 // distributes them among the compaction queues in round-robin fashion.
 40 class G1DetermineCompactionQueueClosure : public HeapRegionClosure {
 41   G1CollectedHeap* _g1h;
 42   G1FullCollector* _collector;
 43   uint _cur_worker;
 44 
 45   inline void free_empty_humongous_region(HeapRegion* hr);
 46 
 47   inline bool should_compact(HeapRegion* hr) const;
 48 
 49   // Returns the current worker id to assign a compaction point to, and selects
 50   // the next one round-robin style.
 51   inline uint next_worker();
 52 
 53   inline G1FullGCCompactionPoint* next_compaction_point();
 54 
 55   inline void add_to_compaction_queue(HeapRegion* hr);
 56 
 57 public:
 58   G1DetermineCompactionQueueClosure(G1FullCollector* collector);
 59 
 60   inline bool do_heap_region(HeapRegion* hr) override;
 61 };
 62 
 63 class G1FullGCPrepareTask : public G1FullGCTask {
 64   volatile bool     _has_free_compaction_targets;
 65   HeapRegionClaimer _hrclaimer;
 66 
 67   void set_has_free_compaction_targets();
 68 
 69 public:
 70   G1FullGCPrepareTask(G1FullCollector* collector);
 71   void work(uint worker_id);
 72   // After the Prepare phase, are there any unused (empty) regions (compaction
 73   // targets) at the end of any compaction queues?
 74   bool has_free_compaction_targets();
 75 
 76 private:
 77   class G1CalculatePointersClosure : public HeapRegionClosure {
 78     G1CollectedHeap* _g1h;
 79     G1FullCollector* _collector;
 80     G1CMBitMap* _bitmap;
 81     G1FullGCCompactionPoint* _cp;
 82 
 83     void prepare_for_compaction(HeapRegion* hr);
 84 
 85   public:
 86     G1CalculatePointersClosure(G1FullCollector* collector,
 87                                G1FullGCCompactionPoint* cp);
 88 
 89     bool do_heap_region(HeapRegion* hr);
 90   };
 91 
 92   template <bool ALT_FWD>
 93   class G1PrepareCompactLiveClosure : public StackObj {
 94     G1FullGCCompactionPoint* _cp;
 95 
 96   public:
 97     G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp);
 98     size_t apply(oop object);
 99   };
100 };
101 
102 // Closure to re-prepare objects in the serial compaction point queue regions for
103 // serial compaction.
104 template <bool ALT_FWD>
105 class G1SerialRePrepareClosure : public StackObj {
106   G1FullGCCompactionPoint* _cp;
107   HeapWord* _dense_prefix_top;
108 
109 public:
110   G1SerialRePrepareClosure(G1FullGCCompactionPoint* hrcp, HeapWord* dense_prefix_top) :
111     _cp(hrcp),
112     _dense_prefix_top(dense_prefix_top) { }
113 
114   inline size_t apply(oop obj);
115 };
116 
117 #endif // SHARE_GC_G1_G1FULLGCPREPARETASK_HPP